The usual photographic and cinematographic objective can be sharply focused upon objects in a normal range between infinity and a so-called macro range, the latter being generally defined as lying between the image-ratio limits of 1:10 and 1:1. In the case of varifocal or pancratic objectives, in which the image plane does not shift between a telephoto position and a wide-angle position brought about by the concurrent axial displacement of two movable components, focusing within the macro range can be achieved by axially shifting one of these movable components beyond the position occupied by it at the wide-angle end of the varifocal range; see, for example, U.S. Pat. No. 3,891,304. Moreover, as proposed in commonly owned application Ser. No. 711,835 filed by me jointly with two others on Aug. 5, 1976, now U.S. Pat. No. 4,110,005 the angle of view can be further increased with the aid of a front attachment to be emplaced on the optical axis, such an attachment being of compact design so that its presence does not significantly extend the overall physical length of the objective.
At the opposite or telephoto end of the varifocal range, however, no such simple attachments have heretofore been available for the purpose of further extending the overall focal length of the system to increase its image scale. In order to operate in such an extended telephoto range, telescope-type front attachments of considerable axial length had to be used. The presence of such a device not only complicates handling of the camera but also tends to destabilize same, thereby aggravating the risk of blurring which commonly exists to a greater or lesser extent in any objective of large focal length.